gas milage

hi, i have been noticing that my gas milage has not been the same like been getting worse. and i have no clue where to start thinking or looking and i havn't really been flooring it to much like twice since i refilled (about 4 days ago) and i'm already at about hald way between a quater and a half tank. any suggestion will help dearly

it could be the level sensor in the tank. we need to know what kind of mileage drop youve had. what kind of mileage was it getting before and what is it getting now. you also cant judge it upon each fill up. you have to add at least 3 together with mainly highway with one, mainly city with another, and mixed for another. there are many factors into it.

but only question i can ask to maybe help is, where does the temperature gauge read WHILE DRIVING. i dont want to know where it goes when stopped, i only want to know where it sits when its fully warmed up and your driving down the road above 35mph

my temp guage is exactly half way up an i have milage trouble

it could be the level sensor in the tank. we need to know what kind of mileage drop youve had. what kind of mileage was it getting before and what is it getting now. you also cant judge it upon each fill up. you have to add at least 3 together with mainly highway with one, mainly city with another, and mixed for another. there are many factors into it.

but only question i can ask to maybe help is, where does the temperature gauge read WHILE DRIVING. i dont want to know where it goes when stopped, i only want to know where it sits when its fully warmed up and your driving down the road above 35mph



well before the i could go 200+ miles before it would hit E but now it's at 140 to 160s. (i forgot how to do the math to determine gas milage). my temp stays around 1/4 and 1/2 . and i haven't been on any highways since i bought the car.

all you do to determine gas mileage is to completely fill the tank. then drive it down to 1/4 (i say 1/4 because you shouldnt go below that because you need the gas in the tank to cool the pump or it overheats and dies quicker or rarely can cause a fire). then fill the tank back up. the amount of gas it took to fill the tank back up will be the number you use to divide the miles that were driven on the tank.

how many gallons are you putting in? and you shouldnt be near empty on 200 miles when the car is running fine. unless your level sensor is bad. we have like a 12.5 gallon tank and around E theres like 2.5 gallons still in the tank and the low fuel light doesnt come on until its down to 1.5? or something close to that.

also need year and model

all you do to determine gas mileage is to completely fill the tank. then drive it down to 1/4 (i say 1/4 because you shouldnt go below that because you need the gas in the tank to cool the pump or it overheats and dies quicker or rarely can cause a fire). then fill the tank back up. the amount of gas it took to fill the tank back up will be the number you use to divide the miles that were driven on the tank.

how many gallons are you putting in? and you shouldnt be near empty on 200 miles when the car is running fine. unless your level sensor is bad. we have like a 12.5 gallon tank and around E theres like 2.5 gallons still in the tank and the low fuel light doesnt come on until its down to 1.5? or something close to that.

also need year and model


i try to put in gas around 1/4 usally it is around 7 gallons i belive. it's a 96 sl2. i think it might be a level sensor problems becouase some times it will say that i have half a tank then when i start driving i magicaly have 3/4 of a tank. how many miles should i be getting on one tank?

depends on how well in tune the car is. im getting 35+ in my 97 sl2 with 160,000 miles on it. mine is also a manual so i can control it better. i check my tire pressure very often so that isnt an issue. i have new ignition with spark plugs changed anywhere from 10K-20K no matter what kind it is. i dont keep much of anything loaded in my car, i change my oil too often and i use gas additives quite often and clean intake out and clean throttle body out. ive also got a new exhaust that flows better.

i do a whole load of things to keep mine as good as i can. my intake is so clean. i can also beat the hell out of my car and still pull off very high 30's even into 40's. last time i filled up, i put in a bit over 7 gallons at a 1/4 of a tank and that 7 gallons was good for 286 miles mainly highway with some hard throttle (had fun since another guy was following me to our meet). id say with everything ok ects in check, then anywhere from 30-35, ects and/or ignition bad 20-28, everything new of great quality 35-40's

mine sits 2 ticks above 1/4. weirdest thing though, when the car is warming up(stop-and-go) my secondary fan doesnt kick on until 3/4. If i have the a/c on the temperature gauge doesnt move at all to the warmer. ALSO, my gas mileage has also been slightly questionable. hope i find out whats up

depends on how well in tune the car is. im getting 35+ in my 97 sl2 with 160,000 miles on it. mine is also a manual so i can control it better. i check my tire pressure very often so that isnt an issue. i have new ignition with spark plugs changed anywhere from 10K-20K no matter what kind it is. i dont keep much of anything loaded in my car, i change my oil too often and i use gas additives quite often and clean intake out and clean throttle body out. ive also got a new exhaust that flows better.

i do a whole load of things to keep mine as good as i can. my intake is so clean. i can also beat the hell out of my car and still pull off very high 30's even into 40's. last time i filled up, i put in a bit over 7 gallons at a 1/4 of a tank and that 7 gallons was good for 286 miles mainly highway with some hard throttle (had fun since another guy was following me to our meet). id say with everything ok ects in check, then anywhere from 30-35, ects and/or ignition bad 20-28, everything new of great quality 35-40's




what is the ect?

driver side of head just barely above the trans housing. 2 wires lead to it. very small little thing.

and about the fan........ its meant to kick on at 220 degrees (like practically all cars) which on our gauge shows 3/4. nothing wrong with that. and the reason why temp doesnt go up with a/c on is because the fan runs constantly to keep the condenser cool so you have cool air, which in turn will also cool the radiator.

driver side of head just barely above the trans housing. 2 wires lead to it. very small little thing.

and about the fan........ its meant to kick on at 220 degrees (like practically all cars) which on our gauge shows 3/4. nothing wrong with that. and the reason why temp doesnt go up with a/c on is because the fan runs constantly to keep the condenser cool so you have cool air, which in turn will also cool the radiator.


what is it though and that is it's full name (the ect). and i have 16.24 mpg on city i have not gone on any highways. but that is with reg 80 something octane points (the cheap stuff). i put in premuim this time to see if that helps. since i don't have a big tank it only costed like 7 more bucks for it. and is there any intake ,throttle body cleaner that i can stick in my gas tank like fuel injector cleaner....etc and what makes up the ignition so i can start determainind if it is bad or not

Engine Coolant Temp sensor. ECT

I changed mine about a year ago and it solved a bunch of problem.

I have a '98 SL2 it had about 100k when I changed it, has 115 now.

how much does the ect cost?

not to much... I think it was something like 30$? But it was a year ago so I really don't remember.

alright thanks

yes and if you want it to work right, get it from the dealer. otherwise no reason to replace it because it will most likely fail soon after installing it.

premium gas wont change it since all its there for is for cars that have a higher combustion pressures. all it does it keeps fuel for preigniting/detonating. you can develope hot spots in a higher combustion engine which will ignite a lower octane quicker. premium fuel is just a waste to stick in a car like ours, unless its boosted (turbo, supercharger) or sprayed (nitrous) or has been rebuilt for higher compression (around 12:1).

you can add lucas fuel treatment, seafoam, or marvel mystery oil to the gas. read instructions on it though, i think marvel is the only that comes more concentrated so you dont add the entire bottle. you can get lucas in a bigger bottle, but just use a 3oz they sell. i think you can get any of them now at wal mart. i saw lucas is now on their shelves and marvel has been there but seafoam im not certain on. but wal mart does carry something that seems similar to seafoam, called b12 i think. but you can get any of the stuff through parts stores.

and i bet your ects is bad being that low on mileage, but also replace your plugs (i suggest ac delco rapidfire as ive had a great experience with them as with otehrs, but most go with ngk v-power). next i would also suggest a piston soak, since the car has been running rich. the reason for it is because being so rich means carbon. this carbon has built up around the piston rings and allows oil to be burned much easier and can reduce your compression.

to do the piston soak, use marvel mystery oil or gm tec (top engine cleaner). do this while the car is warm, not hot. pour the fluid down the spark plug hole just enough to soak the piston completely (your case add more so it floods the cylinder more). if you dont add much more then just covering the piston, then you will have to check back every so often to make sure fluid level is still above piston. now after putting the fluid on the piston, put the spark plugs back in. this can create a steam action and should help loosen carbon better. let the fluid soak on the pistons for 12 hours or more, and check back anyways so you know level is still up. after the soaking period is over, pull plugs back out and check to see if there is much fluid left in the cylinders. if not much, then make sure its in a well ventilated area and start it up (my smoke if oil is forced into exhaust). if too much is left in cylinder, then put rags over the plug holes (with fuel pump and ignition module disabled) crank the engine to throw the excess out. and to disable the fuel pump, pull the fuse and to disable the ignition module you can just look down at the coils and notice a set of wires heading to the coils. on ob2 (96-newer) vehicles you will have 1 connection that has a 5.5mm(7/32") bolt holding it down. on ob1 (95-back) you will have 2 connectors that must be removed.

i added prestone fuel injector cleaner/ octane booster ( only one they had left) and that has helped and am at just below halfway on my tank and i have gone 160 miles which is more then i was able to put on with a full tank plus i tryed that shell v power.

well dont put premium in the car. it doesnt do anything but make it harder for the car to ignite the fuel. it doesnt clean the fuel system, increase gas mileage, nore does it improve performance.

and the least i get on half tank is 180 with lots of idling and stop and go. normally is 200-220.

well dont put premium in the car. it doesnt do anything but make it harder for the car to ignite the fuel. it doesnt clean the fuel system, increase gas mileage, nore does it improve performance.

and the least i get on half tank is 180 with lots of idling and stop and go. normally is 200-220.

well right now with v power and the injector cleaner at 1/5 of the tank it has 202 miles i have gone so it did do something

because you have a problem, and hell the injector cleaner could have done that.

i have another question today when i went to autozone they had fuell injector cleaner plus valve cleaner and one more thing i forget would it be bad to put that in plus with the one that is still in my tank?

if its a fuel injector cleaner, it will clean the valves too whether it says it on the front or not. will injector cleaners do what they say, maybe. they could also be a total waste. what you go in there will theorectically do the same as that other stuff.

ok thanks . oy btw about the piston soak can a mechinc do that mainly becouse i don't trust my self to much doing that.